Is app-release.apk zipaligned apk?

I am using Android Studio 1.0.2.
When I click assembleRelease in gradle tasks, two files are generated, app-release-unaligned.apk and app-release.apk. I know app-release-unaligned.apk is unaligned but what is app-release.apk? Is it aligned apk? My build.gradle is like below.